Structure and methodology for fabrication and inspection of photomasks

Abstract

A photomask, method of designing, of fabricating, of designing, a method of inspecting and a system for designing the photomask. The photomask, includes: a cell region, the cell region comprising one or more chip regions, each chip region comprising a pattern of opaque and clear sub-regions corresponding to features of an integrated circuit chip and one or more kerf regions, each kerf region comprising a pattern of opaque and clear sub-regions corresponding to features of an integrated circuit kerf; a clear region formed adjacent to a side of a copy region, the copy region comprising opaque and clear sub-regions that are copies of at least a part of the cell region; and an opaque region between the clear region and the cell region.

1. A method of inspecting a photomask, comprising:
 providing said photomask, said photomask comprising: 
 a cell region, said cell region comprising one or more chip regions, each chip region comprising a pattern of opaque and clear sub-regions corresponding to features of an integrated circuit chip and one or more kerf regions, each kerf region comprising a pattern of opaque and clear sub-regions corresponding to features of an integrated circuit kerf; 
 a clear region formed adjacent to a side of a copy region, said copy region comprising opaque and clear sub-regions that are copies of at least a part of said cell region; and 
 an opaque region between said clear region and said cell region; 
 performing an image scan of said copy region; 
 performing an image scan of a portion of said cell region corresponding to said copy region; 
 performing a comparison comprising a comparing of said image scan of said copy region and said image scan of said corresponding portion of said cell region; and 
 determining locations of potential defects in said corresponding portion of said cell region based on said comparison or both determining said locations of potential defects in said corresponding portion of said cell region and determining corresponding locations of potential defects in said copy region based on said comparison. 
 
   
   
     2. The method of  claim 1 , further including:
 displaying a representations of said image scan of said cell region corresponding to said copy region at said locations or both displaying a representation of said image scan of said cell region corresponding to said copy region at said locations and displaying representations of said image scan of said cell region at said corresponding locations. 
 
   
   
     3. The method of  claim 1 , wherein said copy region comprises a copy of all or less than a whole portion of a kerf region of said one or more kerf regions. 
   
   
     4. The method of  claim 1 , wherein said copy region comprises copy of all or less than a whole portion of a chip region of said one or more chip regions. 
   
   
     5. The method of  claim 1 , wherein said copy region comprises a copy of all or less than a whole portion of a kerf region of said one or more kerf regions and a copy of all or less than a whole portion of a chip region of said one or more chip regions. 
   
   
     6. The method of  claim 1 ,
 wherein said photomask further includes an additional copy region disposed within said clear region, said additional copy region comprising a copy of said copy region; and 
 said method further including: 
 performing an image scan of said additional copy region; and 
 performing an additional comparison, said additional comparison comprising a comparing of said image scan of said corresponding portion of said cell region to said additional image scan of said additional copy region. 
 
   
   
     7. The method of  claim 6 , further including determining locations of potential defects in said corresponding portion of said cell region based on said comparison and said additional comparison or determining locations of potential defects in said corresponding portion of said cell region, determining locations of potential defects in corresponding locations of said copy region, and determining locations of potential defects in additional corresponding locations of said additional copy region based on said comparison and said additional comparison. 
   
   
     8. The method of  claim 7 , further including:
 performing a second additional comparison, said second additional comparison comprising a comparing of said image scan data of said copy region to said image scan data of said additional copy region 
 determining locations of potential defects in said corresponding portion of said cell region based on said comparison, said additional comparison and said second additional comparison or determining locations of potential defects in said corresponding portion of said cell region, determining corresponding locations of potential defects in said copy region, and determining additional corresponding locations of potential defects in said additional copy region based on said comparison, said additional comparison and said second additional comparison.